API MPMS 4.7 2009 pdf download.Manual of Petroleum Measurement Standards Chapter 4—Proving Systems Section 7—Field Standard Test Measures.
3.2 calibrated volume Also defined as the field standard test measure base volume (BMV); the delivered volume of a field standard test measure, at its reference temperature, between its defined “full and empty” levels. 3.3 calibration A set of operations which establish, under specified conditions, the relationship between the values indicated by a measuring device and the corresponding known values indicated when using a suitable measuring standard. 3.4 cessation of main flow During the draining of a field standard test measure, the moment when the full discharging water stream “breaks” and becomes a small trickle. 3.5 clingage The film of liquid that adheres to the inside surface of a field standard test measure after it has been drained and is considered empty. 3.6 contained volume The volume of liquid (at the reference temperature) held by field test measure filled to the zero reference mark. It is larger than the delivered volume due to clingage of liquid to the inside walls of the test measure. It is also the volume of liquid necessary to fill a clean, dry, empty, test measure to the zero reference mark on the neck scale. “Contained volume” was previously described as “to contain.” The contained volume is not used in the calibration of provers. 3.7 delivered volume The volume of liquid (at the reference temperature) that exits a test measure when it is emptied from its full condition and drained in accordance with the prescribed draining time. In previous standards and certifications’ “delivered volume” was described as “to deliver.” The delivered volume is the only volume used in the calibration of provers. 3.8 field standard test measure A volumetric, non-pressurized, cylindrical, metal container, with a cylindrical neck containing a gauge glass and scale. Designed to stringent specifications, it “contains” or “delivers” an exact volume between a fixed bottom or a bottom shut-off valve and an upper-neck scale reading. 3.9 high-resolution type A field standard test measure
4 Equipment 4.1 General Design specifications for test measures shall be in accordance with this standard and the latest edition of NIST Handbook 105-3. 4.2 Materials and Fabrication A vessel used as a field standard test measure shall be constructed of corrosion-resistant stainless steel. All parts of the main body of the test measure shall be made of the same material. All interior seams shall be filled and ground smooth enough to prevent any entrapment of air, liquid, or foreign material. Fabrication shall ensure that no pockets, dents, or crevices are present that may entrap air or liquid or impair the proper filling or draining of the standard. Any horizontal cross-section shall be circular, and the shape of the vessel shall permit complete emptying and draining. Dimensional requirements for USC units and SI units are shown in Table 1a and Table 1b of NIST Handbook 105-3. See Figure 1 and Figure 2 for typical test measures used for prover calibrations. Where appropriate, reinforcing bands shall be used to prevent distortion of the measure or field standard when it is full of liquid. The opening at the top of the neck shall be structurally durable because of the thickness of the metal, or it shall be reinforced. The bottom of the field standard test measure shall be designed to prevent distortion when it is filled with liquid and prevent damage during use. A field standard test measure in use shall be leveled and stand solidly on a surface with its vertical axis normal to that surface. 4.3 Gauge Glass A field standard test measure shall be equipped with a gauge glass mounted on the side of the neck (see Figure 3). This gauge glass shall be made of borosilicate type glass or equivalent, and shall be free from any irregularities or defects that will distort the appearance of the liquid surface. Any gauge glass made of a substitute material shall be impervious to petroleum products.